Various types of “flavored” drinking straws are known. By the term “flavored”, we mean that an additional substance of some nature has been placed within the drinking straw such that the substance comes into contact with the beverage as the drinker sucks the beverage through the straw. The additional substance may be placed within the straw by various types of inserts, various types of internal coating methods, or various types of external structures that communicate with the interior of the straw.
There are several disadvantages, however, with these known straws. First, the flow of the beverage through the straw may be obstructed when the additional substance is added as part of an internal insert. The insert may cause difficulty or require additional force as the user tries to suck the beverage through the insert. In the case of the interior coating methods, the straw is generally coated after the manufacturing process is complete. This extra coating step, however, may add considerable time and expense to the manufacturing process. Finally, the cost in terms of manufacture and materials is often prohibitive with the use of the known external structures.
What is desired, therefore, is a method and an apparatus for coating the interior surface of a straw with an additional substance. Preferably the method and the apparatus should not materially increase the time of manufacture, increase the cost of manufacture, or decrease the production capacity. Further, the method and the apparatus should coat the additional substance on the interior surface of the straw in a substantially uniform manner.